Nanoparticle-Based Shear-Thickening Materials

ABSTRACT

A composition includes an aqueous colloidal dispersion of a nanomaterial. The nanomaterial includes, disposed on a surface of the nanomaterial, a first coupling agent including silane and a functional group including an amino acid. The nanomaterial includes, disposed on the surface of the nanomaterial, a second coupling agent including silane and a polymer with a molecular weight between 1,000 and 20,000.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit of priorityto U.S. application Ser. No. 16/654,678, filed on Oct. 16, 2019, whichis a divisional of U.S. application Ser. No. 15/812,720, now issued asU.S. Pat. No. 10,480,281 on Nov. 19, 2019, which claims the benefit ofpriority to U.S. Application Ser. No. 62/422,250 entitled“Nanoparticle-Based Shear-Thickening Materials”, filed on Nov. 15, 2016,the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

This specification relates to shear-thickening materials for use inoilfield applications, for example, for aiding in hydrocarbon extractionfrom subterranean zones.

BACKGROUND

Non-Newtonian fluids can have properties of a liquid and of a solid.Unlike Newtonian fluids, the viscosity of non-Newtonian fluids can varywith shear rate. Shear rate is a velocity gradient measured across thediameter of a fluid-flow channel, such as a pipe or an annulus. Dilatantfluids are non-Newtonian fluids that exhibit shear-thickening behavior.In other words, the viscosity of a dilatant fluid increases withincreasing shear rate. Non-Newtonian fluids are complex and can beuseful in oilfield applications. Integrating non-Newtonian fluidmechanics with reservoir characteristics can improve hydrocarbonrecovery in various stages of the lifespan of a producing reservoir.

SUMMARY

The present disclosure describes technologies relating to aqueouscolloidal dispersions of nanomaterials. Certain aspects of the subjectmatter described here can be implemented as a composition including anaqueous colloidal dispersion of a nanomaterial. The nanomaterialincludes, disposed on a surface of the nanomaterial, a first couplingagent including silane and a functional group including an amino acid,and a second coupling agent including silane and a polymer with amolecular weight between 1,000 and 20,000.

This, and other aspects, can include one or more of the followingfeatures. The amino acid can be a polar amino acid.

The polymer can be polyethylene glycol or polyethylene oxide.

The aqueous colloidal dispersion can be a shear-thickening material.

A potential of hydrogen (pH) of the aqueous colloidal dispersion can bein a range of 9 to 10.

Heating the aqueous colloidal dispersion to a temperature above 90degrees Celsius (° C.) can cause a viscosity of the aqueous colloidaldispersion to reversibly increase by a factor of 1.5 to 15.

Applying a shear on the aqueous colloidal dispersion can cause aviscosity of the aqueous colloidal dispersion to reversibly increase bya factor of 1.1 to 3.

A ratio between the first coupling agent and the second coupling agentdisposed on the surface of the nanomaterial can be between 1:1 and 20:1.

The nanomaterial can include silica nanoparticles having an averageparticle size of equal to or less than approximately 1 micrometer (μm).

The silica nanoparticles can have an average particle size in a range of60 nanometers (nm) to 1,000 nm.

Certain aspects of the subject matter described here can be implementedas a method. A nanomaterial is formed, in which an average particle sizeof the nanomaterial is equal to or less than approximately 1 μm. Formingthe nanomaterial includes disposing, on a surface of a silicananoparticle, a first coupling agent including silane and a functionalgroup including an amino acid and disposing, on the surface of thesilica nanoparticle, a second coupling agent including silane and apolymer with a molecular weight between 1,000 and 20,000. Thenanomaterial is dispersed in a fluid including water to form an aqueouscolloidal dispersion.

This, and other aspects, can include one or more of the followingfeatures. The amino acid can be a polar amino acid.

The polymer can be polyethylene glycol or polyethylene oxide.

The aqueous colloidal dispersion can be a shear-thickening material.

A ratio between the first coupling agent and the second coupling agentdisposed on the surface of the silica nanoparticle can be between 1:1and 20:1.

Certain aspects of the subject matter described here can be implementedas a method which includes introducing an aqueous colloidal dispersionto a subterranean zone. The aqueous colloidal dispersion includes ananomaterial including, disposed on a surface of the nanomaterial, afirst coupling agent including silane and a functional group includingan amino acid and a second coupling agent including silane and a polymerwith a molecular weight between 1,000 and 20,000.

This, and other aspects, can include one or more of the followingfeatures. A ratio between the first coupling agent and the secondcoupling agent disposed on the surface of the nanomaterial can bebetween 1:1 and 20:1.

The aqueous colloidal dispersion can be mixed with a cement beforeintroducing the aqueous colloidal dispersion to the subterranean zone.

The aqueous colloidal dispersion can be a shear-thickening material, andapplying a shear on the aqueous colloidal dispersion can cause aviscosity of the aqueous colloidal dispersion to reversibly increase bya factor of 1.1 to 3.

Heating the aqueous colloidal dispersion to above 90° C. can cause aviscosity of the aqueous colloidal dispersion to reversibly increase bya factor of 1.5 to 15.

The details of one or more implementations of the subject matter of thisspecification are set forth in the accompanying drawings and thedescription. Other features, aspects, and advantages of the subjectmatter will become apparent from the description, the drawings, and theclaims.

DESCRIPTION OF DRAWINGS

FIG. 1 is an example of a well.

FIG. 2 is a flow chart of an example method for forming an aqueouscolloidal dispersion of nanomaterials.

FIGS. 3A and 3B are schematic diagrams of nanomaterial.

FIGS. 4A and 4B are images of an aqueous colloidal dispersion ofnanomaterials.

FIG. 5 is a graph of viscosities of various aqueous colloidaldispersions of nanomaterials with various shear rates applied.

FIG. 6 is a graph of viscosities of an aqueous colloidal dispersion ofnanomaterial at different temperatures with various shear rates applied.

DETAILED DESCRIPTION

A shear-thickening material (also referred as a dilatant material) is amaterial in which viscosity increases with an increasing rate of shearstrain or applied shear stress. Any increase in viscosity due to shearis reversible, such that the viscosity decreases when the shear isreduced or stopped. A shear-gelling material is a material that can forma gel when shear stress is applied. Similarly, any gel formed due toshear is reversible, such that the gel disappears or is destroyed whenthe shear is reduced or stopped. Such materials can be useful inoilfield applications, such as in drilling, well or reservoir treatment,hydraulic fracturing, completions, and enhancing hydrocarbon recovery.

This disclosure describes aqueous colloidal dispersions (also referredas colloids) of nanomaterials, such as silica (SiO₂) nanoparticles, thatcan viscosify under shear or can produce or form a gel under shear.Silica nanoparticles can be grafted with polymers that exhibitshear-gelling and shear-thickening properties. There are various factorsthat can affect the viscosity of such fluids, that is, aqueous colloidaldispersions of nanomaterials. For example, an increase in concentrationof nanomaterials or an increase in molecular weight of the polymersgrafted onto the nanomaterials can increase the viscosity of thecolloidal dispersion. A way to improve the shear-thickening capabilityof such colloids is to introduce charged (that is, having a positive ornegative charge) moieties along the backbone of the polymers graftedonto the nanomaterials. The charged nature of the polymer backbone canlead to intramolecular electrostatic repulsions between the moietiesalong the backbone and intermolecular electrostatic repulsions betweenpolymers grafted on the same silica nanoparticle or neighboring silicananoparticles, thereby increasing the hydrodynamic volume of the polymercoil, which can increase the viscosity of the colloid.

The subject matter described in this specification can be implemented inparticular implementations, so as to realize one or more of thefollowing advantages. The compositions described in this disclosure canbe used as shear-thickening materials. During drilling of a well, theshear-thickening material can be used to prevent unwanted flow, such aslost circulation when drilling mud flows into a formation withoutreturning to the surface. The use of shear-thickening material canensure safe operation and prevent or mitigate the possibility of upsetsthat can result in costly losses in production and repairs. For example,the shear-thickening material can be used as a blowout preventer to dealwith any extreme, erratic pressures or uncontrolled flow, such as when agas cap is reached during drilling. The shear-thickening material can beused as a cement additive to delay hardening of the cement. Duringenhanced oil recovery, the shear-thickening material can be used toincrease the viscosity of an injection fluid, thereby preventing ormitigating the potential of fingering, which can result in prematurewater breakthrough.

FIG. 1 illustrates an example of a hydrocarbon extraction system 10including a well 12. The well 12 can be in a wellbore 20 formed in asubterranean zone 14. The subterranean zone 14 can include, for example,a formation, a portion of a formation, or multiple formations in ahydrocarbon-bearing reservoir from which recovery operations can bepracticed to recover trapped hydrocarbons. In some implementations, thesubterranean zone 14 includes an underground formation of naturallyfractured rock containing hydrocarbons (for example, oil, gas, or both).For example, the subterranean zone 14 can include a fractured shale. Insome implementations, the well 12 can intersect other suitable types offormations, including reservoirs that are not naturally fractured in anysignificant amount.

The well 12 can include a casing 22 and well head 24. The wellbore 20can be a vertical, horizontal, deviated, or multilateral bore. Thecasing 22 can be cemented or otherwise suitably secured in the well bore12. Perforations 26 can be formed in the casing 22 at the level of thesubterranean zone 14 to allow oil, gas, and by-products to flow into thewell 12 and be produced to the surface 25. Perforations 26 can be formedusing shape charges, a perforating gun or otherwise. In some cases, thewell 12 is completed openhole without a casing.

A work string 30 can be disposed in the well bore 20. The work string 30can be coiled tubing, sectioned pipe or other suitable tubing. Packers36 can seal an annulus 38 of the well bore 20 uphole of and down hole ofthe subterranean zone 14. Packers 36 can be mechanical, fluid inflatableor other suitable packers. One or more pump trucks 40 can be coupled tothe work string 30 at the surface 25. The pump trucks 40 pump fluid 58down the work string 30, for example, to pump cement into the well bore20. The pump trucks 40 can include mobile vehicles, equipment such asskids or other suitable structures.

One or more instrument trucks 44 can also be provided at the surface 25.The instrument truck 44 can include a control system 46. The controlsystem 46 can monitor and control the pump trucks 40 and fluid valves,for example, to stop and start pumping fluid into the well bore 20. Thecontrol system 46 communicates with surface and subsurface instrumentsto monitor and control a process, such as a well treatment process. Insome implementations, the surface and subsurface instruments includesurface sensors 48, down-hole sensors 50 and pump controls 52.

This description describes compositions that can be used asshear-thickening materials in a well bore 20 formed in a subterraneanzone 14. The compositions can include an aqueous colloidal dispersion ofsilica nanoparticles and can be flowed into the subterranean zone (forexample, a reservoir). The silica nanoparticles have an average particlesize of equal to or less than approximately 1 micrometer (μm). In thisspecification, “approximately”, “approximate”, or “approx.” means adeviation or allowance of up to 10 percent (%) and any variation from amentioned value is within the tolerance limits of any machinery used tomanufacture the part. The silica nanoparticles can be functionalizedwith two different coupling agents that each include silane. Thecoupling agents can be disposed on a surface of the silica nanoparticlesby adsorption, chemical reaction, or a combination of these. A firstcoupling agent can include a polar amino acid, such as histidine,glutamine, asparagine, serine, threonine, tyrosine, cysteine,tryptophan, arginine, lysine, aspartic acid, or glutamic acid. A secondcoupling agent can include a polymer. The polymer can have a molecularweight that is between 1,000 and 20,000 (units for molecular weight aregrams per mole). In some cases, the polymer of the second coupling agentis polyethylene glycol (PEG). In some cases, the polymer of the secondcoupling agent is polyethylene oxide (PEO). The molecular weight of thepolymer of the second coupling agent disposed on the surface of thesilica nanoparticles can affect the viscosity of an aqueous colloidaldispersion of such nanoparticles. For example, utilizing a secondcoupling agent including a polymer with a larger molecular weight canincrease the viscosity of the resulting aqueous colloidal dispersion.The nanomaterial (that is, the silica nanoparticles with the first andsecond coupling agents disposed on their surfaces) can be dispersed in afluid which includes water to form an aqueous colloidal dispersion. Thisaqueous colloidal dispersion can be a shear-thickening material. In someimplementations, the aqueous colloidal dispersion has a potential ofhydrogen (pH) in a range of 9 to 10.

FIG. 2 shows a flow chart for a method 200 for forming an aqueouscolloidal dispersion of nanomaterial. At 201, a nanomaterial is formed.The nanomaterial includes silica nanoparticles whose average particlesize is equal to or less than approximately 1 Forming the nanomaterialincludes at 201 a, disposing a first coupling agent on a surface of thesilica nanoparticle. The first coupling agent includes silane and afunctional group, and the functional group includes an amino acid. Insome implementations, the amino acid is a polar amino acid, such ashistidine, glutamine, asparagine, serine, threonine, tyrosine, cysteine,tryptophan, arginine, lysine, aspartic acid, or glutamic acid. Formingthe nanomaterial includes at 201 b, disposing a second coupling agent onthe surface of the silica nanoparticle. The second coupling agentincludes silane and a polymer with a molecular weight between 1,000 and20,000. In some implementations, the polymer is PEG. In someimplementations, a ratio between the first and second coupling agentsdisposed on the surface of the silica nanoparticle is between 1:1 and20:1. For example, the ratio between the first and second couplingagents disposed on the surface of the silica nanoparticle is 19:1, 9:1,3:1, or 3:2. To dispose the first and second coupling agents on thesurface of the silica nanoparticles, the silica nanoparticles can bedispersed in a solvent and then mixed with the first and second couplingagents. An additive can be added to the mixture to alter a pH of themixture. The pH can be altered in order to promote or acceleratereactions involved with coupling the silanes (that is, of the first andsecond coupling agents) to the silica nanoparticles. For example, anadditive can be added to the mixture to change the pH of the mixture tobe in a range of 9 to 10. The mixture can be stirred for sufficient time(for example, approximately 12 hours) to allow the first and couplingagents to dispose on the surface of the silica nanoparticles byadsorption, chemical reaction, or both. After the mixture has beenstirred for sufficient time to allow the first and second couplingagents to dispose on the surface of the silica nanoparticles, the silicananoparticles can be separated from the remaining mixture, for example,by centrifugation, lyophilization (that is, freeze-drying), orcombinations of both.

At 203, the nanomaterial is dispersed in a fluid which includes water toform an aqueous colloidal dispersion. The concentration of nanomaterialin the aqueous colloidal dispersion can affect the viscosity of theaqueous colloidal dispersion. For example, increasing the concentrationof nanomaterial in the aqueous colloidal dispersion can increase theviscosity of the aqueous colloidal dispersion. The aqueous colloidaldispersion can be introduced to a subterranean zone. For example, theaqueous colloidal dispersion can be pumped into a wellbore formed withina subterranean zone. In some implementations, the aqueous colloidaldispersion is mixed with a cement before introduction to thesubterranean zone. The aqueous colloidal dispersion can be ashear-thickening material. Applying a shear on the aqueous colloidaldispersion can cause a viscosity of the aqueous colloidal dispersion toreversibly increase by a factor of 1.1 to 3. Applying a shear can beunderstood to mean applying any kind of shear, such as applying a shearrate, applying a shear force, or applying a shear stress. For example,an aqueous colloidal dispersion of the nanomaterial described previously(this specific example referred as Colloid A) can have a viscosity of 1centipoise (cP) when no shear is applied and a viscosity of 3 cP when ashear rate of 450 reciprocal seconds (s⁻¹) is applied. Assuming allother conditions remain the same, if the shear rate is stopped, theviscosity of Colloid A can decrease and return to 1 cP. Heating theaqueous colloidal dispersion to a temperature above 90 degrees Celsius(° C.) can cause the viscosity of the aqueous colloidal dispersion toreversibly increase by a factor of 1.5 to 15. For example, Colloid A canhave a viscosity of 1 cP at 20° C. and a viscosity of 10 cP at 100° C.Assuming all other conditions remain the same, if the temperature ofColloid A drops below 90° C. (for example, back to 20° C.), theviscosity of Colloid A can decrease and return to 1 cP. The applicationof shear and heating to a temperature above 90° C. can have a cumulativeeffect on the viscosity of such aqueous colloidal dispersions of thepreviously described nanomaterials. For example, Colloid A can have aviscosity of 1 cP at 20° C. when no shear is applied and a viscosity of30 cP when a shear rate of 450 s⁻¹ is applied at 100° C. Assuming allother conditions remain the same, if the temperature of Colloid A dropsbelow 90° C. (for example, back to 20° C.) and the shear rate isstopped, the viscosity of Colloid A can decrease and return to 1 cP.

FIGS. 3A and 3B show schematic diagrams of neighboring silicananoparticles of an aqueous colloidal dispersion as previously describedin this description. FIG. 3A shows the silica nanoparticles when noshear is applied to the aqueous colloidal dispersion, and FIG. 3B showsthe silica nanoparticles when shear is applied to the aqueous colloidaldispersion. In FIG. 3A, the second coupling agents including a polymerwith a molecular weight of 1,000 to 20,000 (depicted by the longercurves attached to the surface of the silica nanoparticles) preventneighboring silica nanoparticles from associating with each other. InFIG. 3B, the applied shear causes the second coupling agents tocollapse, and the polar amino acids of the first coupling agents(depicted by the shorter curves attached to the surface of the silicananoparticles) can interact and form hydrogen bonding with other firstcoupling agents on neighboring silica nanoparticles. The interparticlehydrogen bonding can increase the viscosity of the bulk fluid (that is,the aqueous colloidal dispersion of nanomaterial). Stopping or takingaway the shear from the aqueous colloidal dispersion can cause thenanoparticles to disassociate from each other, reverting back to what isshown in FIG. 3A, where the polymer chains prevent the nanoparticlesfrom associating with each other. FIGS. 4A and 4B show dynamic lightscattering images of an implementation of the aqueous colloidaldispersion of silica nanoparticles described. FIG. 4A shows the colloidwhen no shear is applied, and FIG. 4B shows the colloid when shear isapplied.

Example 1

The first coupling agent was prepared by adding 10 milliliters (mL) ofdimethylformamide (DMF) solvent to 1.07 mL of(3-glycidyloxypropyl)trimethoxysilane (1 equivalent) and 1 gram (g) ofhistidine (1.5 equivalent), along with an excess of sodium carbonate(Na₂CO₃). This mixture was stirred for 12 hours at room temperature(approximately 23° C.), so that the first coupling agent includingsilane and the polar amino acid (histidine) could form.

The second coupling agent included silane and PEG. 2.0 g of 1 μm silicaparticles were dispersed in 20 mL of ethanol solvent. This dispersion ofsilica particles in ethanol solvent was utilized as a base fluid in thefluids shown in the following table. The amounts of first and secondcoupling agents were added to the base fluid and are shown in milligrams(mg) in the following table.

Ratio of 1^(st) to Total silane Fluid 1^(st) coupling 2^(nd) coupling2^(nd) coupling weight % number agent agent agents relative to silica #119 1 approx. 95:5  1% #2 18 2 approx. 90:10 1% #3 16 4 approx. 75:25 1%#4 14 6 approx. 60:40 1%

To each of the fluids (#1, #2, #3, and #4) shown in the table, 1 mL ofwater (H₂O) was added in order to dissolve the second coupling agent.Acidic acid was added to each fluid, such that the pH of each of thefluids were approximately 4.5. Each of the fluids were sealed andstirred for 12 hours at room temperature (approximately 23° C.). Then,each of the fluids were centrifuged at 5,000 revolutions per minute(rpm) for 5 minutes to cause the precipitate (that is, the silicaparticles treated with the first and second coupling agents) to separatefrom the supernatant (that is, the remaining solution), and thesupernatant was discarded. The precipitate was re-dispersed in ethanoland centrifuged, again. This procedure of re-dispersing the precipitatein a fluid followed by centrifugation was repeated: three times withethanol and then two times with water. After the final centrifugation ofthe precipitate and removal of the supernatant, the silica particleswere lyophilized in a freeze dryer overnight in order to remove anyresidual water. FIG. 5 shows a data graph plotting the viscosities ofeach of the fluids (#1, #2, #3, and #4) shown in the table at variousshear rates.

Example 2

2.0 g of 1 μm silica particles were dispersed in 20 mL of ethanolsolvent. A quantity of a coupling agent including silane and PEG and aquantity of (3-aminopropyl)triethoxysilane (APTES) were added to thedispersion to satisfy a mass ratio of 8:1, respectively, followed by anaddition of 1 mL of water in order to dissolve the coupling agentincluding silane and PEG. The dispersion was then stirred for 12 hoursat room temperature (approximately 23° C.) and then stirred for 5 hoursat 80° C. The dispersion was cooled to room temperature (approximately23° C.) and centrifuged at 5,000 rpm for 5 minutes to cause theprecipitate to separate from the supernatant, and then the supernatantwas discarded. The precipitate was re-dispersed in 20 mL of water, andan excess of histidine was added. The mixture of particles, water, andhistidine was refluxed for 12 hours in order to dehydrate (that is,remove water from) the particles and then cooled to room temperature(approximately 23° C.). FIG. 6 shows a data graph plotting theviscosities of the prepared colloid at room temperature (approximately23° C.) and at 100° C. at various shear rates.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of the subjectmatter or on the scope of what may be claimed, but rather asdescriptions of features that may be specific to particularimplementations. Certain features that are described in thisspecification in the context of separate implementations can also beimplemented, in combination, in a single implementation. Conversely,various features that are described in the context of a singleimplementation can also be implemented in multiple implementations,separately, or in any suitable sub-combination. Moreover, althoughpreviously described features may be described as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can, in some cases, be excised from thecombination, and the claimed combination may be directed to asub-combination or variation of a sub-combination.

Particular implementations of the subject matter have been described.Other implementations, alterations, and permutations of the describedimplementations are within the scope of the following claims as will beapparent to those skilled in the art. While operations are depicted inthe drawings or claims in a particular order, this should not beunderstood as requiring that such operations be performed in theparticular order shown or in sequential order, or that all illustratedoperations be performed (some operations may be considered optional), toachieve desirable results.

Accordingly, the previously described example implementations do notdefine or constrain this disclosure. Other changes, substitutions, andalterations are also possible without departing from the spirit andscope of this disclosure.

What is claimed is:
 1. A method comprising: forming a nanomaterial,wherein an average particle size of the nanomaterial is equal to or lessthan approximately 1 μm, the forming comprising: disposing, on a surfaceof a silica nanoparticle, a first coupling agent comprising silane and afunctional group comprising an amino acid; and disposing, on the surfaceof the silica nanoparticle, a second coupling agent comprising silaneand a polymer with a molecular weight between 1,000 and 20,000; anddispersing the nanomaterial in a fluid comprising water to form anaqueous colloidal dispersion.
 2. The method of claim 1, wherein theamino acid is a polar amino acid.
 3. The method of claim 1, wherein thepolymer is polyethylene glycol or polyethylene oxide.
 4. The method ofclaim 1, wherein the aqueous colloidal dispersion is a shear-thickeningmaterial.
 5. The method of claim 1, wherein a ratio between the firstcoupling agent and the second coupling agent disposed on the surface ofthe silica nanoparticle is between 1:1 and 20:1.
 6. A method comprisingintroducing an aqueous colloidal dispersion to a subterranean zone, theaqueous colloidal dispersion comprising a nanomaterial including,disposed on a surface thereof: a first coupling agent comprising silaneand a functional group comprising an amino acid; and a second couplingagent comprising silane and a polymer with a molecular weight between1,000 and 20,000.
 7. The method of claim 6, wherein a ratio between thefirst coupling agent and the second coupling agent disposed on thesurface of the nanomaterial is between 1:1 and 20:1.
 8. The method ofclaim 6, further comprising mixing the aqueous colloidal dispersion witha cement before introducing the aqueous colloidal dispersion to thesubterranean zone.
 9. The method of claim 6, wherein the aqueouscolloidal dispersion is a shear-thickening material, and applying ashear on the aqueous colloidal dispersion causes a viscosity of theaqueous colloidal dispersion to reversibly increase by a factor of 1.1to
 3. 10. The method of claim 6, wherein heating the aqueous colloidaldispersion to above 90° C. causes a viscosity of the aqueous colloidaldispersion to reversibly increase by a factor of 1.5 to 15.